This invention relates to matrix transformers, and in particular to matrix transformers having multiple turn primaries, either single coil windings as for a full bridge, half bridge or forward converter or multiple coil windings as for push-pull windings, split windings or a forward converter having a reset winding.
FIG. 1 shows a prior art magnetic core 1 as may be used to make a matrix transformer. FIG. 2 shows a phantom view 4 of the magnetic core 1 of FIG. 1 further comprising first and second secondary windings 2 and 3. FIG. 3 shows a prior are “element” 5 of a matrix transformer comprising a pair of magnetic cores 1, 1 which are the magnetic core 1 of FIG. 1 each further comprising first and second secondary windings 2 and 3. The secondary windings 2 and 3 may be connected in various arrangements as required by a particular application.
FIG. 4 shows a prior art matrix transformer 10 comprising five magnetic elements 5—5 which are the magnetic element 5 of FIG. 3. A primary winding 11 is wound by hand through the five elements 5—5 of the matrix transformer 10. Winding the primary winding 11 is a labor intensive manual operation. It is time consuming and requires considerable skill, yet the result is often messy. If the wires of the primary winding 11 cross in the matrix transformer 10, it can be difficult or impossible to get the required number of turns, and their arrangement is some-what random yielding inconsistent product.